A new study finds that retrofitting old buildings is almost always more eco-friendly than building new ones, and provides the most immediate bang for the buck in the fight against climate change. The implication: Save old cities and we might spare the planet as well.

Oh, New York. You think that you've got a cool new idea, but always (always!) Europe beats you to it. NYC’s been getting all kinds of excited about its High Line park, an abandoned train platform converted into a wonderland of local plants, awesome places to sit and people-watch, and hibiscus ice pop vendors. But at TreeHugger, Alex Davies points out that NYC is just a couple decades late to the elevated park party. For almost 20 years, Parisians have been enjoying a stroll above city streets on the Viaduc des Arts. And just like the High Line, the elevated platform is a converted rail line.

Jason Griffiths is an assistant professor of design at Arizona State, and apparently living in the middle of all that desert sprawl got to him after a while. In the early aughts he jumped into a car, drove all over the country, and made a discovery so banal it’s practically a tautology: Suburbia is the same everywhere.